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So, OK, Cutting corners....

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ronzet

ronzet

Jedi Knight
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LBC fans...

I guess I am just waxing philosphic...

I have this great MGA, as you know, that has gone through a complete frame off rebuild....Many dollars yet need to be invested to finish although I do drive it, sans completed interior..

I also have this driver 66 MGB....

This is the sitrep... the B has great compression (150psi in each cylinder) does not burn oil, runs great actually... BUT
once warm, the Oil Pressure hovers around 2 psi... Ergo, needs new bearings (rod and main)...

This is the proposition.. pull the engine, flip it over, remove the crank, take it to the machine shop and mill it... replace it (with appropriate bearings), put it back in the car and drive away....

So, assuming that I want to invest my major dollars into the A... what is the downside?????

Thanks...
 
Ron,
The compression numbers suggest an overhaul of the top end at some time earlier.

Given that then a refresh on the bottom end to restore oil pressure makes sense and I see nothing wrong with the way you are suggesting.

One point though is there may well be wear on the ancillary bits like the camshaft bearings and distributor drive wear.
A straight bearing refresh will not address these points.

Is the engine ready for a complete overhaul?
If so then I would be looking at pressure test and crack test the block , align boring the bearing seats and having the head done the same way.

Cheers , Pete.
 
Bah, replace the bearings and give it a go. Cheep enough and one days work. Prob will be good for another 40k.
 
My bad. :devilgrin:

If you go to the trouble to pull it out and put it on a stand, it's TIME to disassemble, inspect and refresh ALL the wear parts. Cam bearings, timing chain, rings... If you just toss a set of bearings at it, you still have a tired bottom end. Too much work to risk having to do it all again in a short period of time.

Why not hunt down another short block, rebuilt that and do a one day swap? Then you can do this one up correctly and wrap it in plastic as a stand-by.
 
I think once you get a gander at the bearing and the shape of the crank journals you'll have your answer, maybe you should do a clearence check on those bearing to see what your clearence is, use palstagauge, even if the bearing is worn that will give you data to look at, too much rod bearing clearence either from worn bearings/damage journal is the #1 reason for a drop in oil pressure. I'm guessing at 2 pounds of oil pressure your finding will not be pretty, don't be surprised to find a spun bearing, if so, then a complete teardown will be a must as the engine will be full of bearing debris.
 
My Granddaddy used to say that if you go to the troble of taking it out, go to the trouble of building it correctly....he always felt that was money ahead!
 
And he was correct. But then the title is "cutting corners".
 
There is nothing worse than throwing your money out the window. If you go through the effort to pull the motor you should definitely go through the motor or you are wasting your time. The engine has enough wear, obviously, that there is probably significant contaminates in the block. These engines are very easy to rebuild and not that expensive if you have the machine shop only do the work you dont have the tools for (e.g. boil the block, bore the cylinders, etc). End result, you have a motor to enjoy and not languish over "what if". :thumbsup: MHO
Ed
 
Gentlemen....

Thanks for the thoughtful responses.. AND thanks for listening to be complain...

This poor little LBC has been 'kept on the road' for the last three years while I have lavished my time and money into her older sister -- the A...

In order to 'keep her on the road' :square:-- about three years ago, I dropped the pan and replaced the rod bearings with the same size as the old ones... improved the OP a bit and I have been able to drive it -- with a worried expression -- since...

I know that the BEST way to take care of the problem is to tear it out and rebuild it -- COMPLETELY...

However, once I do that, I know that I will not stop with the engine... I will begin the entire rebuild process on it, body, electrical, mechanical, interior....<span style="font-weight: bold">without really intending too</span>.. ,

<span style="font-weight: bold">You guys KNOW what I am talking about</span>.... It's the, <span style="font-style: italic">'Well while I am at it I should replace (or rebuild) this, Oh and then that...ad infinitum'</span> There are very few of us that can just go part way... just not in our nature. Otherwise we would be driving late model Miatas or BMWs like any sane person would.

AND by the time I put the completely rebuilt engine back into her... It will be three of four years later, many thousands of dollars, and I will have my completely restored 66 B to drive around...

OMG HELP ME!!! :wall:

<span style="font-weight: bold"> Now that I have vented... </span> I will probably leave well enough alone, drive her once in a while, devote the time to the A and, once the A is finished, tear the B apart and restore her to her previous glory and all that that entails....


Oh, TONY!! When I posted this I said to my self that I knew what our Guru Tony would say.... AND I WAS RIGHT... :thumbsup:
 
Ron,
Yes I fully understand your predicament.
Where to begin is simple enough but where to stop is the hard question.

Cheers , Pete.
 
I'd pull her, flip her over & check the journals then pop the pistons & check them...at best you'll be ablr to just replace the bearings & rings - at moste block, you'll need to turn the crank & bore th....if it turns out the worst, toss that block & grab one that will only need honing & reringing!

That's the cheapest way to go, IMHO
 
I agree with Tony here, if you just want to pull the stuff out of the bottom and do a quick, "git 'er done" and back on the road to be driven for another couple (or 30?) thousand miles.

But if you are mainly worried about getting into the other "might as well" jobs, take the car somewhere that it is impractical to work on, pull the engine and take it home to do a total job done right. Here, all we need to do this time of the year is leave the rest of the car outside, where it is too cold to work on. You may need to leave it somewhere else...I use my in-laws garage myself LOL.

This way, you don't need to see the rest of the car (out of sight, out of mind) and are less inclined to do the other stuff...just rebuild the engine, take it back to the car and put it back in there or have the car towed back to your place and give yourself a day to put it back in.

All of this is for those of us who have no self-control over those "might as well" jobs...trust me, I know from experience! You might also discover that pulling the engine/tranny is not that difficult and you can do it again if you ever have time and money to do those other jobs.

Good luck...and keep focused...self-control! you can do it!
 
Really depends on why the oil pressure is low.

You are playing Russian Roulette with the odds somewhat loaded in your favour. Most likely reason for low pressure is worn bearings. If that is the case, and the bottom end doesn't look like it was hit with a firehose spraying brass bits when you pull the pan, you may get lucky.

If the low pressure is from something else - worn oil pump, for instance (which of course should be checked while you are in there, you might roll the dice and lose.

Even if you win, you don't know how sloppy the timing chain is (probably never touched) or if the tensioner shoe is down to metal, or...or.....

I've done quick and dirty and won when I had to, but I'd side with the guys telling you that if you take the time and money to do it right, you'll have something you can rely on for years.
 
Gentlemen,

Sagely advice ....

I like Bruce's idea of a remote location... However, I am helping my business partner restore a 58 100-6 at his house soooo, remote is out...

You are right that removing and replacing the engine and tranny isn't a <span style="font-weight: bold">major major </span>job and I do have a hoist... I had forgotten how easy these cars are to work on...

The key problem is room... I have one bay of my three car garage, the other two for my wife's Mercedes and the other (a one car section) is used for a workout room. Sooo, I am swapping turns for the A and the B in the garage. My CC&Rs do not permit me to work on the car in the driveway and the Assoc Board do frequent walk-arounds.

Anyway... although I have rebuilt the suspension and cleaned up the under-carriage I do not intend to do a complete teardown of this car as I did my A.

Therefore... I think that the best of both worlds will be to pull the engine and tranny, Rebuild it COMPLETELY (as in clutch, t/o bearing, and total rebuild of the engine). While out I will disassemble, clean, restore, and paint (BRG) the engine compartment. Restore the engine and tranny where it belongs and drive to the body shop (when $$$ allow) where it will be body-worked and painted... Then, new interior and off I go.. except for the $$$$$s, I am ready to go... all the while my A will be under cover in the driveway.... :wall:

<span style="font-weight: bold">Any words of wisdom or warnings for this approach...</span>
 
Sounds like a plan.
 
Bill,

By the way... although a bad oil pump could be a culprit, the fact that I replaced the bearings, as commented in an earlier post, and the OP increased somewhatfor about 120 miles until the bearing lash once again became excessive... Although, when I rebuild the engine, the oil pump will be replaced as a matter of course...

Thanks again.
 
You'll have to pull the head to pull the crank, so why not check the bores while you'r ein there. That'll tell you if a rebuild is in order, or if you can "just get by". Certainly you can cut corners to get the oil pressure up, but for how long? If you only intend to put on a few thousand miles a year, it may get you by for 5-10 years when you'll be psychologically ready for another full resto. :smile:
 
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